Water motor

ABSTRACT

AN EASILY AMINTAINED, EFFICIENT, LOW TURBULENCE WATER MOTOR IN WHCIH WATER IS PROJECTED FROM A NOZZLE TO THE BLADES OF AN IMPELLER AND EXPELLED THROUGH AN OUTLET IN STRAIGHT ALIGNMENT WITH THE NOZZLE. THE WATER ENTERS THE NOZZLE THROUGH AN INLET CHAMBER INTEGRAL WITH THE BODY OF THE MOTOR AND PROVIDING A SUMP FOR RETENTION OF DIRT OR OTHER PARTICULATE MATTER IN THE WATER.

1, 1972 w. K. HODGMAN, JR 337E013 WATER MOTOR Filed Oct. 28, 1970 FIG. I

WATER INLET WATER OUTLET 4\ I02 INVENTOR WILLIS K. HODGMAN, JR.

WATER BY M/ M OUTLET 4/ 5 E ATTORNEYS United States Patent 3,676,015WATER MOTOR Willis K. Hodgman, Jr., Taunton, Mass., assignor to HodgmanManufacturing Company, Inc., Taunton,

Mass.

Filed Oct. 28, 1970, Ser. No. 84,750 Int. Cl. F01d 15/06, 9/00 US. Cl.415-202 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTIONThe field of this invention generally comprises water motors, and thisinvention is more particularly concerned wtih a motorsuitable forrotating the striker arm of a fire alarm gong or the like.

In the typical alarm gong application the gong is mounted on the wall ofa building, such as the outside wall. The motor is mounted on theopposite side or inside of the wall, and a shaft from the motor to thestriker arm passes through a tube or pipe that provides a convenientmeans for supporting the bodies of the motor and gong. Water pipeconnections are made to the motor, and the motor is fitted with an inletnozzle for projecting water against an impeller. There is also an inletchamber having a sump for retention of particles of dirt or otherforeign matter in the water to prevent the possibility of clogging theinlet nozzle. The inlet nozzle is adapted to restrict, shape and directthe water jet or stream in a desired manner against the blades or vanesof the impeller.

Prior water motors of the foregoing general type are limited in terms oftheir efliciency of operation because energy is lost as a result ofturbulence which has a braking elfect on the impeller. In a typicalmotor the impeller takes the form of an overshot or undershot wheel,with the nozzle directing the jet or stream in a horizontal directionagainst the blades or vanes and being discharged and drained in avertical direction from the bottom of the motor body or housing. Thischange in the direction of water flow, coupled with the dispersion ofthe stream by the blades or vanes, absorbs substantial energy and makesnecessary a substantial flow of water to obtain a sufficiently audibleand reliable operation of the gong. This in turn results in thesubstantial size and cost of the water motor gong as a unit.

It is a principal object of this invention to improve the efficiency ofoperation of the water motor, thereby permitting the use of a muchsmaller water motor for the gong, the smaller motor requiring a lowerrate of water flow for proper operation of the gong.

'SUMMARY OF THE INVENTION This invention accomplishes the above andother objects that will be evident from the following detaileddescription, by a substantial improvement in the control of the jet orstream of water as it passes through the motor. This stream is directedvertically by a nozzle in a straight line toward the water outlet fromthe motor, and no change of direction is imparted to the stream withinthe region of the impeller except for the effect of the impinge-3,676,015 Patented July 11, 1972 ment of the water upon the vanes orblades of the impeller itself.

This improvement in operation is achieved by a novel location of thewater nozzle and water outlet in a straight line configurationhorizontally offset with reference to the axis of the striker arm shaft,through an improved inlet chamber configuration including a passage fordirecting the water to the nozzle in direct alignment with the wateroutlet, and at the same time providing ready access to the nozzle forinspection, cleaning and replacement.

Other features of the invention will be apparent from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an end elevation of the watermotor, partially broken away and partially in section, viewed in thedirection of the axis of the striker arm shaft.

FIG. 2 is a side elevation in section taken on line 2-2 Of FIG. I].-

DESCRIPTION OF THE PREFERRED EMBODIMENT The water motor gong in thepreferred embodiment of FIGS. 1 and 2 is of the type used in connectionwith automatic water sprinkler systems for fire protection. It comprisesa gong designated generally at 12 and a water motor designated generallyat 14, respectively mounted on opposite sides of a building wall 16,usually an exterior wall. The gong has a cast aluminum wall plate 18having a tapped boss 20 in alignment with a round hole 22 passingtransversely through the wall. The plate 18 is threaded to a mountingpipe 24, and the pipe is held fast to the wall by means of a lock nut 26and washer 28.

The wall plate 18 has an outwardly projecting boss 30 having a centraltapped hole, and upon this boss a cast aluminum hell or gong 32 ismounted by means of a machine screw 34. Preferably, the plate 18 is ofcircular shape and the boss 30 is central to it, accommodating acircular gong 32, and the gong has a flange or rim 36 projecting towardthe wall into close proximity with the plate 18 without touching it.

The water motor 14 has a cast aluminum body 38 having a tapped boss 40received on a projecting threaded end of the pipe 24, being located andheld in place on the pipe by a lock nut 42.

A rotatable striker arm shaft 44 is journaled in bearings respectivelymounted in the body 38 and wall plate 18. An oil-impregnated bronzebushing 46 is fitted in a bore in the wall plate 18, and a flangedoil-impregnated bronze bushing 48 is similarly fitted in a bore in thebody 38.

A molded plastic driver 50 is connected to the shaft 44 by a pin 52 androtatably received within the bushing 46. A cast bronze striker arm 54is fastened by a machine screw 56 to the driver 50, and has a steelstriker holder 58 secured near its end, the holder loosely retaining alaminated phenolic resin striker 60 in position to strike the skirt orflange portion 36 of the gong. The striker has a circular peripheralshape with a central bore 62- substantially larger in diameter than astern portion 64 forming part of the holder 58, whereby the rotation ofthe arm 54 imparts a centrifugal force to the striker causing it to moveradially a sulficient distance to strike the gong, being deflectedradially inwardly by the gong until the arm 54 has passed its point ofclosest proximity to the gong during each rotation.

Turning next to a more complete description of the water motor 14, castaluminum impeller 65 has a hub 66 over which a brass journal sleeve 67is push-fitted, the sleeve 67 being in sliding contact with the bushing48. The hub 66 has a central hole 68 with one or more flats engagingcorresponding flats on the shaft 44, whereby rotation of the impellercauses rotation of the shaft. The impeller also has a central axiallyprojecting button 69. This button engages the surface of a fiat accessplate 70 mounted to the body 38 by four machine screws 71 and a rubbersealing gasket 72. The access plate holds the impeller in position toengage the end of the shaft 44 for rotation as above described, andprovides a means for readily gaining access to the impeller forinspection, removal and cleaning.

The body 38 defines a semi-toroidal shaped impeller channel 74 closed bythe plate 70. The body 38 also has a water outlet comprising a boss 80with a tapped opening in communication with the channel 74 and normallyoriented downwardly in a position permitting it to drain the channelcompletely. A suitable water outlet pipe 82 may be threaded into thisopening for conducting the water to a drain.

An inlet chamber 84 is formed integrally with the body 38, and has alower portion forming a sump 86 and an upper portion comprising a battle88 and a passage 90 above the bafile. The inlet chamber has a boss 92with a tapped opening for receiving a water inlet pipe 94. The waterenters the inlet chamber in such a direction that it is initiallybaffled to permit solid particles to settle into the sump 86, the waterthen bypassing the batlle 88 and entering the passage '90. The sump maybe periodically drained and cleaned by removal of a threaded cleanoutplug 96.

A brass nozzle or orifice 98 is fitted in a countersunk, counterboredhole 100 in the upper portion of the body, the nozzle having a centralhole coaxial with the hole '100, the latter connecting the passage 90with the impeller channel 74. The aperture of the nozzle or orifice, aswell as that of the hole 100, is on a straight vertical line passingthrough the axis of the water outlet pipe 82. Access to the nozzle forinspection, cleaning and replacement is provided by a threaded plug 102threaded into the body 38. The axis of this plug is also in a straightline with the nozzle and the outlet pipe.

The impeller 65 has an integral hub portion 104 and a number of equallyspaced radial blades or fins 106 each of which fills a substantialportion of the cross section of the channel 74. The outer portion of thehub 4 has an annular cylindrical ilange portion 108 passing over and inclose contiguity with a radially-extending annular flange 110 on thebody 38, thus forming a baffle preventing the forcible projection of thestream of water on to the bushing 48 and bearing sleeve 67.

The operation of the water motor will be evident from the foregoingdescription. It will be noted in particular that the incoming water isinitially baffled within the inlet chamber 84, then bypasses the baffle88 into the passage 90, then passes through the nozzle 98 into contactwith the blades 106, thereafter passing directly out of the water outletpipe 82. This straight-line impingement with the impeller results inminimal turbulence of the water, thereby minimizing the braking effectof turbulence on the impeller and greatly increasing the efliciency ofthe motor.

It will be noted that in the usual application the water motor isoperated by the water supply of a sprinkler sys- 4 tern. The alarmsounds continuously during the period that water is flowing out of thesprinkler system as a result of the operation of one or more sprinklerheads because of fire, and operation of the alarm also occurs in casesof accidental flow of water from the sprinkler system.

It has been found that the increase in the efliciency of operation ofthe water motor over prior types permits it to be constructed to asubstantially smaller scale than water motors previously used foroperating similar gongs.

Servicing of the impeller, as well as inspection or replacement thereof,are readily permitted by removal of the screws 71 and the plate 70, thuspermitting the impeller to be slidably pulled from engagement with theshaft 44 and the bushing 48. Thus all of the parts of the water motorare readily accessible for maintenance purposes.

I claim:

1. A water motor for operating an alarm gong or the like having, incombination,

a body having a shaft bushing, annular impeller channel coaxial withsaid bushing, an inlet chamber vertically positioned in said bodyexternal to said impeller channel, said inlet chamber having a lowerportion forming a sump, an upper portion including a generallyhorizontal bafile with a passage bypassing the bafile and a water inletentering said inlet chamber between said lower portion and said bafile,said passage having a nozzle for direction of water to said impellerchannel, said body having a water outlet in a straight line with thedirection of water fiow through said nozzle, said line being generallyparallel to a vertical line between said upper and lower portions ofsaid inlet chamber,

a shaft rotatable in and extending from said bushing,

and an impeller secured to the shaft and having plural mutually spacedradial blades within said impeller channel.

2. The combination according to claim '1, in which the inlet chamber isintegral with the body and a partition in said body comprises a wallportion of said impeller channel and said inlet chamber.

3. The combination according to claim 1, with access means in the wallof the passage, said access means being located in a straight line withsaid nozzle and water out let and providing access to said nozzle.

References Cited UNITED STATES PATENTS 661,512 11/1900 Fullmer 415-202959,352 5/ 1910 Kellett 415-202 1,940,344 12/ 1933 Broderick 415-20 3FOREIGN PATENTS 199,560 11/1938 Switzerland 415202 HENRY F. RADUAZO,Primary Examiner U.S. Cl. X.R.

